CN109386986B

CN109386986B - Two-pipe heating recovery multi-split air conditioner system and air conditioner outdoor unit thereof

Info

Publication number: CN109386986B
Application number: CN201811227642.XA
Authority: CN
Inventors: 颜利波; 杨国忠; 王命仁
Original assignee: Midea Group Co Ltd; GD Midea Heating and Ventilating Equipment Co Ltd
Current assignee: Midea Group Co Ltd; GD Midea Heating and Ventilating Equipment Co Ltd
Priority date: 2018-10-22
Filing date: 2018-10-22
Publication date: 2021-05-04
Anticipated expiration: 2038-10-22
Also published as: CN109386986A

Abstract

The invention provides a two-pipe heating recovery multi-split air conditioner system and an air conditioner outdoor unit thereof, wherein the air conditioner outdoor unit comprises: a main circulation flow path and an enhanced vapor injection flow path. The main circulation flow path comprises an enhanced vapor injection compressor, a reversing device and an outdoor heat exchanger which are connected through pipelines, and the two ends of the main circulation flow path are respectively communicated with the inlet and the outlet of the refrigerant distribution device through a refrigerant output pipe and a refrigerant input pipe; the enhanced vapor injection flow path comprises a flash evaporator and an outdoor throttling device, an inlet of the flash evaporator is communicated with the refrigerant input pipe through a first pipeline, an outlet at the gas side is connected with an air injection port of the enhanced vapor injection compressor through a second pipeline, an outlet at the liquid side is connected with the input end of the outdoor heat exchanger through a third pipeline, and the outdoor throttling device is arranged on the third pipeline. The invention uses the technology of the enhanced vapor injection compressor and adds the flash evaporator and the outdoor throttling device, so that the heating, air injection and enthalpy increasing functions are added to the two-pipe heating and recovering multi-split air-conditioning system, and the low-temperature heating capacity and the heating effect of the system are obviously improved.

Description

Two-pipe heating recovery multi-split air conditioner system and air conditioner outdoor unit thereof

Technical Field

The invention relates to the technical field of air conditioners, in particular to a two-pipe heating recovery multi-split air conditioner system and an air conditioner outdoor unit thereof.

Background

At present, the existing two-pipe heating recovery multi-split air conditioner system does not have a low-temperature strong heat machine type, and under a low-temperature environment, the low pressure is low due to low environmental temperature, the return air density is small, the refrigerant circulation volume is small, and therefore the problem of insufficient heating capacity exists.

Disclosure of Invention

In order to solve at least one of the above technical problems, an object of the present invention is to provide an outdoor unit of an air conditioner for a two-pipe heat recovery multi-split system.

Another object of the present invention is to provide a two-pipe heat recovery multi-split air conditioning system including the outdoor unit of an air conditioner.

In order to achieve the above object, a first aspect of the present invention provides an outdoor unit of an air conditioner, which is used in a two-pipe heat recovery multiple split air conditioner system, where the two-pipe heat recovery multiple split air conditioner system includes a plurality of indoor units of the air conditioner and a refrigerant distribution device connecting the outdoor unit of the air conditioner and the plurality of indoor units of the air conditioner, and the outdoor unit of the air conditioner includes: the main circulation flow path comprises an enhanced vapor injection compressor, a reversing device and an outdoor heat exchanger which are connected through pipelines, and two ends of the main circulation flow path are respectively communicated with an inlet and an outlet of the refrigerant distribution device through a refrigerant output pipe and a refrigerant input pipe; and the enhanced vapor injection flow path comprises a flash evaporator and an outdoor throttling device, an inlet of the flash evaporator is communicated with the refrigerant input pipe through a first pipeline, an outlet at the gas side of the flash evaporator is connected with an air injection port of the enhanced vapor injection compressor through a second pipeline, an outlet at the liquid side of the flash evaporator is connected with the input end of the outdoor heat exchanger through a third pipeline, and the outdoor throttling device is arranged on the third pipeline.

According to the air-conditioning outdoor unit for the two-pipe heat recovery multi-split air-conditioning system, the jet enthalpy-increasing flow path is added to the air-conditioning outdoor unit by using the jet enthalpy-increasing compressor technology and adding the flash evaporator and the outdoor throttling device, so that the two-pipe heat recovery multi-split air-conditioning system is added with a heat jet enthalpy-increasing function, the refrigerant circulation quantity during low-temperature heating operation of the two-pipe heat recovery multi-split air-conditioning system is obviously increased, the low-temperature heating operation range of the two-pipe heat recovery multi-split air-conditioning system is further expanded, and the heating effect of the two-pipe heat recovery multi-split air-conditioning system is obviously improved.

Specifically, in the existing two-pipe heat recovery multi-split air-conditioning system, because a return pipe on the outdoor unit side of an air-conditioning unit only has low-pressure refrigerant and cannot provide medium-pressure refrigerant for an air injection port of an enhanced vapor injection compressor, the enthalpy injection is difficult to realize at the air injection port of the compressor, so the enhanced vapor injection low-temperature forcing technology is only applied to a heat pump and a three-pipe heat recovery system at present, and the two-pipe heat recovery multi-split air-conditioning system with enhanced vapor injection function does not exist; and this application is through improving air condensing units for two pipe heating recovery multi-split air conditioning units system has possessed the enhanced vapor injection function, thereby adopts the enhanced vapor injection technique to realize the breakthrough of two pipe heating recovery multi-split air conditioning units system low temperature intense heat technique's application, has satisfied two pipe heating recovery multi-split air conditioning units system operation requirement under lower outdoor environment temperature, has improved the travelling comfort of heating.

The air conditioner outdoor unit comprises a main circulation flow path and an enhanced vapor injection flow path, wherein the main circulation flow path comprises an enhanced vapor injection compressor, a reversing device and an outdoor heat exchanger which are connected through pipelines, one end of the main circulation flow path is communicated with an inlet of a refrigerant distribution device through a refrigerant output pipe and conveys refrigerants to the refrigerant distribution device, the refrigerant distribution device distributes the refrigerants entering and exiting the air conditioner indoor units, and then the refrigerants after heat exchange are sent back to the air conditioner outdoor unit through a refrigerant input pipe to finally complete circulation; in the process of refrigerant flowing, all parts on the main circulation flow path and all parts on the enhanced vapor injection flow path are correspondingly matched, so that the two-pipe heat recovery multi-split air conditioner system realizes the refrigerating and heating functions (such as a pure refrigerating mode, a pure heating mode, a main refrigerating mode, a main heating mode and the like).

Compared with the prior art, the flash evaporator and the outdoor throttling device are additionally arranged on the outdoor unit of the air conditioner, the inlet of the flash evaporator is communicated with the refrigerant input pipe of the outdoor unit of the air conditioner through the first pipeline, the gas side outlet is connected with the air jet opening of the jet enthalpy-increasing compressor through the second pipeline, the liquid side outlet is connected with the input end of the outdoor heat exchanger through the third pipeline, and the outdoor throttling device is arranged on the third pipeline, so that after the refrigerant flowing back to the outdoor unit of the air conditioner from the refrigerant input pipe passes through the flash evaporator to be divided into two paths in the heating operation (including a pure heating mode and a main heating mode), the gaseous refrigerant can directly flow to the air jet opening of the compressor, and the liquid refrigerant flowing to the outdoor heat exchanger can pass through the outdoor throttling device to be throttled and depressurized and then enters the outdoor heat exchanger to be evaporated and absorbed heat and then flows back to the return air port of the compressor, so that, thereby realizing the enhanced vapor injection of the compressor. In other words, the present application is equivalent to adding a flash evaporator and an outdoor throttling device to a return pipe (i.e. a refrigerant input pipe) of the existing air conditioner outdoor unit, so that at least a part of the throttling function of the system is performed at the air conditioner outdoor unit side during heating operation (including a pure heating mode and a main heating mode), and thus the refrigerant pressure at the refrigerant input pipe is higher than the pressure at the outlet of the outdoor heat exchanger, and becomes a medium-pressure two-phase refrigerant instead of a low-pressure refrigerant in the prior art; the medium-pressure two-phase refrigerant is subjected to gas-liquid separation in the flash evaporator, the generated medium-pressure gaseous refrigerant enters an air jet port of the compressor for enhanced vapor injection, and the generated medium-pressure liquid refrigerant enters the outdoor heat exchanger for heat exchange after throttling and pressure reduction and flows back to a return air port of the compressor.

It can be understood that the refrigerant input pipe and the refrigerant output pipe are respectively provided with a stop valve, which respectively correspond to a low pressure valve and a high pressure valve in the prior art; in addition, the high-pressure refrigerant, the medium-pressure refrigerant and the low-pressure refrigerant in the application only indicate the relative pressure of the refrigerants at different positions in the refrigerant circulation flow path in the operation process of the air conditioner, and the air conditioner is not limited by specific numerical values.

In addition, the outdoor unit of the air conditioner in the above technical solution provided by the present invention may further have the following additional technical features:

in the above technical scheme, the second pipeline is provided with a first control valve capable of controlling the second pipeline to be on or off.

The first control valve is arranged on the second pipeline and can control the on-off of the second pipeline, so that the selective on-off of the second pipeline is realized, and therefore, under the condition that the system does not need enthalpy injection and air supplement during refrigeration operation and the like, the second pipeline can be disconnected through the first control valve, influence on other functions (such as a pure refrigeration mode, a main refrigeration mode and the like) of the system is prevented, and the reliability of the system is improved.

In the above technical solution, the first control valve is an electromagnetic valve.

The electromagnetic valve is used as the first control valve, so that the on-off of the second pipeline can be effectively controlled, and the system can be matched conveniently to realize automatic control. Of course, the first control valve is not limited to the solenoid valve, and may be other types of valves as long as the on/off of the second pipeline can be controlled.

In any of the above technical solutions, the third pipeline is further provided with a first check valve, and the first check valve is in one-way communication in a direction from the liquid side outlet of the flash evaporator to the input end of the outdoor heat exchanger.

The first one-way valve is arranged on the third pipeline and is in one-way conduction in the direction from the liquid side outlet of the flash evaporator to the input end of the outdoor heat exchanger, so that only the liquid refrigerant output by the flash evaporator can flow to the outdoor throttling device and the outdoor heat exchanger in sequence and cannot flow in the reverse direction, and the outdoor throttling device only plays a throttling and pressure reducing role during heating operation; and the high-pressure refrigerant discharged by the compressor during the refrigeration operation can only flow to the outdoor heat exchanger and can not flow to the flash evaporator through the outdoor throttling device to cause unnecessary pressure loss or gas leakage and other adverse phenomena, thereby ensuring the normal operation of the refrigeration function of the system.

In the above technical solution, the first check valve is located between the liquid side outlet of the flash evaporator and the outdoor throttling device.

The first one-way valve is arranged between the liquid side outlet of the flash evaporator and the outdoor throttling device, so that the refrigerant can only flow to the outdoor throttling device from the liquid side outlet of the flash evaporator and cannot flow reversely, and the influence on the energy efficiency of the system due to unnecessary pressure loss or air leakage caused by the fact that the high-pressure refrigerant discharged from the compressor enters the outdoor throttling device is further prevented.

In any of the above solutions, the outdoor throttling device comprises a throttling element; or, the outdoor throttling device comprises a plurality of throttling elements connected in parallel; or, the outdoor throttling device comprises at least one throttling element and a shunt electromagnetic valve, and the at least one throttling element is connected with the shunt electromagnetic valve in parallel.

The outdoor throttling device mainly has the functions of throttling and pressure reducing, and the specific form is not limited. Such as: the refrigerant throttling device can only comprise one throttling element, also can comprise a plurality of throttling elements connected in parallel, also can be a parallel combination of the throttling element and a flow dividing electromagnetic valve (namely, the electromagnetic valve playing a flow dividing role and preventing all refrigerants from entering the throttling element), and the like, and also can be in other forms; the forms of the throttling elements are not limited, such as capillary tubes, electronic expansion valves and the like, which are not listed, and as the throttling and pressure reducing functions can be realized without departing from the design concept and the purpose of the invention, the throttling and pressure reducing functions are all within the protection scope of the invention, and the specific forms and the number can be reasonably adjusted according to the specific structure and the requirements of products in the actual production process.

In any of the above technical solutions, the reversing device includes a four-way valve, a second one-way valve, a third one-way valve, a fourth one-way valve, a fifth one-way valve and a sixth one-way valve, a first port of the four-way valve is communicated with an exhaust port of the enhanced vapor injection compressor through a fourth pipeline, a second port of the four-way valve is respectively connected with an input end and an output end of the outdoor heat exchanger through a fifth pipeline and a sixth pipeline, a third port of the four-way valve is respectively communicated with the refrigerant input pipe and the refrigerant output pipe through a seventh pipeline and an eighth pipeline, a fourth port of the four-way valve is communicated with a return port of the enhanced vapor injection compressor through a ninth pipeline, and an output end of the outdoor heat exchanger is further communicated with the refrigerant output pipe through a tenth pipeline; the second one-way valve is arranged on the fifth pipeline and is communicated in a one-way mode in the direction from the second port to the input end of the outdoor heat exchanger; the third one-way valve is arranged on the sixth pipeline and is communicated in a one-way mode in the direction from the output end of the outdoor heat exchanger to the second port; the fourth one-way valve is arranged on the seventh pipeline and is communicated in a one-way mode in the direction from the refrigerant input pipe to the third port; the fifth one-way valve is arranged on the eighth pipeline and is communicated in a one-way mode in the direction from the third port to the refrigerant output pipe; and the sixth one-way valve is arranged on the tenth pipeline and is communicated in a one-way mode in the direction from the output end of the outdoor heat exchanger to the refrigerant output pipe.

The reversing device comprises a four-way valve and a plurality of one-way valves, and the four-way valve is matched with the one-way valves, so that the functions of selective on-off and one-way conduction of all pipelines of the outdoor unit of the air conditioner are realized, and the normal realization of all functions of refrigeration, heating and the like of the system is further ensured.

When pure heating operation, the first port and the third port intercommunication of cross valve, second port and fourth port intercommunication, first control valve is opened, and the refrigerant flow direction of system is: the high-temperature and high-pressure gaseous refrigerant is discharged from an exhaust port of the enhanced vapor injection compressor, reaches a first port of the four-way valve through a fourth pipeline, flows out of a third port of the four-way valve, and reaches a refrigerant output pipe through an eighth pipeline and a fifth one-way valve; then the refrigerant enters each air conditioner indoor unit for condensation and heat release after entering a refrigerant distribution device for distribution, and then is changed into a medium-pressure two-phase refrigerant by the refrigerant distribution device to reach a refrigerant input pipe; the medium-pressure two-phase refrigerant reaches an inlet of the flash evaporator through a first pipeline, is separated in the flash evaporator, and the generated medium-pressure gaseous refrigerant is discharged from an outlet at the gas side, reaches an air jet of the compressor through a second pipeline and a first control valve and enters a compression cavity of the compressor; the generated medium-pressure liquid refrigerant is discharged from a liquid side outlet, reaches an outdoor throttling device through a third pipeline and a first one-way valve, is throttled and depressurized, then enters an outdoor heat exchanger to be evaporated and absorb heat, is changed into a low-pressure gaseous refrigerant, then reaches a second port of the four-way valve through a sixth pipeline and a third one-way valve, flows out from a fourth port of the four-way valve, and returns to a gas return port of the compressor through a ninth pipeline.

When pure refrigeration operation, the first port and the second port intercommunication of cross valve, third port and fourth port intercommunication, first control valve is closed, and the refrigerant flow direction of system is: the high-temperature and high-pressure gaseous refrigerant is discharged from an exhaust port of the enhanced vapor injection compressor, reaches a first port of the four-way valve through a fourth pipeline, flows out of a second port of the four-way valve, enters the outdoor heat exchanger through a fifth pipeline and a second one-way valve, is condensed and released in the outdoor heat exchanger to become a high-temperature and high-pressure liquid refrigerant, and reaches a refrigerant output pipe through a tenth pipeline and a sixth one-way valve; then the refrigerant enters a refrigerant distribution device for distribution, enters each air conditioner indoor unit for evaporation and heat absorption to be changed into low-pressure gaseous refrigerant, and then reaches a refrigerant input pipe through the refrigerant distribution device; the low-pressure gaseous refrigerant reaches the third port of the four-way valve through the seventh pipeline and the fourth one-way valve, flows out of the fourth port of the four-way valve and returns to the air return port of the compressor through the ninth pipeline.

When the main heating operation, the first port and the third port intercommunication of cross valve, second port and fourth port intercommunication, first control valve is opened, and the refrigerant flow direction of system is: the high-temperature and high-pressure gaseous refrigerant is discharged from an exhaust port of the enhanced vapor injection compressor, reaches a first port of the four-way valve through a fourth pipeline, flows out of a third port of the four-way valve, and reaches a refrigerant output pipe through an eighth pipeline and a fifth one-way valve; then the refrigerant enters a refrigerant distribution device for distribution and then enters an air conditioner indoor unit for heating operation for condensation and heat release to be changed into a medium-pressure two-phase refrigerant, the medium-pressure two-phase refrigerant enters the refrigerant distribution device for supercooling and then is divided into two paths, one path of the refrigerant flows to an outlet of the refrigerant distribution device through a throttling element, the other path of the refrigerant enters the air conditioner indoor unit for refrigerating operation for evaporation and heat absorption to be changed into a low-pressure gaseous refrigerant and then reaches the outlet of the refrigerant distribution device, and the two paths of the refrigerant reach a refrigerant input pipe in a medium-pressure two-; then the medium-pressure two-phase refrigerant reaches an inlet of the flash evaporator through a first pipeline, is separated in the flash evaporator, and the generated medium-pressure gaseous refrigerant is discharged from an outlet at the gas side, reaches an air jet of the compressor through a second pipeline and a first control valve and enters a compression cavity of the compressor; the generated medium-pressure liquid refrigerant is discharged from a liquid side outlet, reaches an outdoor throttling device through a third pipeline and a first one-way valve, is throttled and depressurized, is changed into a low-pressure refrigerant, then enters an outdoor heat exchanger to be evaporated and absorbed to be changed into a low-pressure gaseous refrigerant, then reaches a second port of the four-way valve through a sixth pipeline and a third one-way valve, flows out of a fourth port of the four-way valve, and returns to a return air port of the compressor through a ninth pipeline.

When the main refrigeration operation, the first port and the second port intercommunication of cross valve, third port and fourth port intercommunication, first control valve is closed, and the refrigerant flow direction of system is: the high-temperature and high-pressure gaseous refrigerant is discharged from an exhaust port of the enhanced vapor injection compressor, reaches a first port of the four-way valve through a fourth pipeline, flows out of a second port of the four-way valve, enters the outdoor heat exchanger through a fifth pipeline and a second one-way valve, is condensed and released in the outdoor heat exchanger to become a high-temperature and high-pressure liquid refrigerant, and reaches a refrigerant output pipe through a tenth pipeline and a sixth one-way valve; after the refrigerant entering the refrigerant distribution device is subjected to gas-liquid separation, the separated liquid refrigerant is throttled and decompressed to enter an air conditioner indoor unit for refrigerating operation to evaporate and absorb heat to be changed into a low-pressure gaseous refrigerant, the low-pressure gaseous refrigerant reaches an outlet of the refrigerant distribution device, the separated gaseous refrigerant enters the air conditioner indoor unit for heating operation to condense and release heat, returns to the refrigerant distribution device for supercooling, then enters the refrigerating indoor unit to evaporate and absorb heat to be changed into the low-pressure gaseous refrigerant, and the low-pressure gaseous refrigerant reaches the outlet of the refrigerant distribution device, and the two paths of low-; then the low-pressure gaseous refrigerant reaches the third port of the four-way valve through the seventh pipeline and the fourth one-way valve, flows out of the fourth port of the four-way valve and returns to the air return port of the compressor through the ninth pipeline.

In the above technical solution, an outlet of the second check valve is located between the outdoor throttling device and an input end of the outdoor heat exchanger.

The outlet of the second one-way valve is arranged between the outdoor throttling device and the input end of the outdoor heat exchanger, so that high-temperature and high-pressure refrigerants discharged by the compressor during the refrigerating operation can not enter the outdoor heat exchanger through the outdoor throttling device, unnecessary pressure loss is avoided, and the refrigerating capacity of the system is improved.

In the above technical solution, the ninth pipeline is further provided with a first gas-liquid separator.

The ninth pipeline is provided with the first gas-liquid separator which can perform gas-liquid separation on the refrigerant returning to the air return port of the compressor, so that the liquid impact phenomenon caused by the liquid refrigerant returning to the air return port of the compressor is prevented, and the use reliability of the compressor is improved.

In the above technical solution, the reversing device further includes a second control valve, two ends of the second control valve are respectively communicated with the exhaust port and the refrigerant output pipe, and the second control valve is in a closed state in the pure refrigeration mode.

The reversing device further comprises a second control valve, two ends of the second control valve are respectively communicated with the air exhaust port of the compressor and the refrigerant output pipe, and the second control valve is in a closed state in the pure refrigeration mode, so that under the condition of at least part of air conditioner indoor units in heating operation (namely pure heating operation, main heating operation and main refrigeration operation), one part of high-temperature and high-pressure gaseous refrigerant exhausted from the air exhaust port of the compressor can directly enter the refrigerant distribution device by opening the second control valve and then enter the heating indoor unit for condensation and heat release, thereby reducing the pressure loss of the high-temperature and high-pressure gaseous refrigerant in the process of reaching the heating indoor unit, improving the heating capacity of the system, and ensuring the realization of functions of main refrigeration and the like of the system. Preferably, the second control valve is a solenoid valve.

Specifically, for the conditions of pure heating operation and main heating operation, the high-temperature high-pressure gaseous refrigerant discharged by the compressor is divided into two paths, and the two paths enter the refrigerant distribution device through the four-way valve and the second control valve respectively, which is equivalent to increase the flow area of the high-temperature high-pressure gaseous refrigerant, so that the pressure loss of the high-temperature high-pressure refrigerant at the outdoor side is reduced; for the condition of main refrigeration operation, high-temperature and high-pressure gaseous refrigerants discharged by the compressor are also divided into two paths, one path of the gaseous refrigerants enters the outdoor heat exchanger through the four-way valve to be condensed and released to become liquid refrigerants and then reaches the refrigerant output pipe, the other path of the gaseous refrigerants reaches the refrigerant output pipe through the second control valve, and the two paths of the gaseous refrigerants are mixed into two-phase refrigerants and enter the refrigerant distribution device; the liquid refrigerant after gas-liquid separation enters the refrigerating inner machine for evaporation and heat absorption, the gas refrigerant after gas-liquid separation enters the heating inner machine for condensation and heat release, the liquid refrigerant after heat exchange can also enter the refrigerating inner machine for heat exchange after being supercooled by the refrigerant distribution device, and the pressure loss of the refrigerant entering the heating inner machine is reduced because the refrigerant entering the heating inner machine does not have the throttling function of the throttling device and the like.

The technical scheme of the second aspect of the invention provides a two-pipe heating recovery multi-split system, which comprises: the outdoor unit of an air conditioner according to any one of the above aspects; the air conditioner indoor units are connected in parallel; and the refrigerant distribution device is arranged between the air conditioner outdoor unit and the plurality of air conditioner indoor units, is used for connecting the air conditioner outdoor unit and the plurality of air conditioner indoor units, and distributes refrigerants entering and exiting the plurality of air conditioner indoor units.

The two-pipe heating recovery multi-split air conditioner system provided by the technical scheme of the second aspect of the present invention includes the air conditioner outdoor unit according to any one of the technical schemes of the first aspect, so that all the beneficial effects of any one of the technical schemes are achieved, and no further description is given here.

In the above technical scheme, the refrigerant distribution device includes a second gas-liquid separator, a main subcooler, a main throttling device, a plurality of refrigeration check valves, a plurality of heating check valves, a plurality of refrigeration solenoid valves and a plurality of heating solenoid valves, which are connected by a pipeline; the inlet of the second gas-liquid separator is communicated with the inlet of the refrigerant distributor device, the liquid side outlet of the second gas-liquid separator is connected to the main path inlet of the main subcooler through a pipeline, the main throttling device is arranged between the main path outlet of the main subcooler and the auxiliary path inlet of the main subcooler, and the auxiliary path outlet of the main subcooler is connected to the outlet of the refrigerant distributor device through a pipeline; the gas side outlet of the second gas-liquid separator is respectively connected to the first ends of the plurality of air-conditioning indoor units through the plurality of heating electromagnetic valves, the second ends of the plurality of air-conditioning indoor units are respectively connected to the main path inlet of the main subcooler through the plurality of heating one-way valves, and the plurality of heating one-way valves are in one-way conduction in the direction from the second ends of the plurality of air-conditioning indoor units to the main path inlet of the main subcooler; the main path outlet of the main subcooler is respectively connected to the second ends of the air-conditioning indoor units through the refrigeration one-way valves, and the refrigeration one-way valves are in one-way conduction in the direction from the main path outlet of the main subcooler to the second ends of the air-conditioning indoor units; the first ends of the air-conditioning indoor units are respectively connected to the outlets of the refrigerant distribution device through the refrigeration electromagnetic valves.

The refrigerant distribution device comprises a second gas-liquid separator, a main subcooler, a main throttling device, a plurality of heating electromagnetic valves, a plurality of refrigerating electromagnetic valves, a plurality of heating one-way valves and a plurality of refrigerating one-way valves, and the components are matched with each other, so that the functions of selective on-off and one-way conduction of all pipelines in the refrigerant distribution device and in each air conditioner indoor unit are realized, and the normal realization of all functions of system refrigeration, heating and the like is further ensured.

When pure heating operation, a plurality of heating solenoid valves are opened, a plurality of refrigeration solenoid valves are closed, and the refrigerant flow direction of air condensing units output is: the high-temperature high-pressure gaseous refrigerant output by the refrigerant output pipe enters a second gas-liquid separator, the high-pressure gaseous refrigerant flowing out of a gas side outlet of the second gas-liquid separator enters a plurality of air-conditioning indoor units through a plurality of heating electromagnetic valves respectively, exchanges heat with indoor heat exchangers of the air-conditioning indoor units, is condensed into high-pressure liquid refrigerant, and then passes through an indoor unit electronic expansion valve to be changed into medium-pressure two-phase refrigerant; and then the refrigerant enters the main subcooler to be subcooled and then flows out of the main outlet, then reaches the outlet of the refrigerant distribution device through the main throttling device and the auxiliary passage of the main subcooler, and returns to the refrigerant input pipe of the air-conditioning outdoor unit. In the process, the opening degree of the main throttling device is kept fully opened, so that the resistance is reduced as much as possible, the pressure loss of the medium-pressure two-phase refrigerant is reduced as much as possible, and the pressure of the two-phase refrigerant reaching the flash evaporator is ensured to be enough to realize subsequent enhanced vapor injection.

When pure refrigeration operation, a plurality of refrigeration solenoid valves are opened, a plurality of heating solenoid valves are closed, and the refrigerant flow direction of the air conditioner outdoor unit output is as follows: high-temperature and high-pressure liquid refrigerant output by a refrigerant output pipe enters a second gas-liquid separator, the high-pressure liquid refrigerant flowing out of a liquid side outlet of the second gas-liquid separator reaches a main path inlet of a main subcooler, enters the main subcooler for subcooling, and then the liquid refrigerant flowing out of a main path outlet is divided into two paths, one path of the liquid refrigerant is throttled by a main throttling device and depressurized, absorbs heat by an auxiliary path of the main subcooler and then is changed into low-pressure gaseous refrigerant to reach an outlet of a refrigerant distribution device; the other path of refrigerant flowing out of the main path outlet enters a plurality of air conditioner indoor units through a plurality of refrigeration one-way valves, flows through an electronic expansion valve of the indoor unit for throttling and pressure reduction, then enters an indoor heat exchanger for evaporation and heat absorption to be changed into low-pressure gaseous refrigerant, and then reaches the outlet of the refrigerant distribution device through a plurality of refrigeration electromagnetic valves.

When the main heating operation is performed, the heating electromagnetic valve corresponding to the heating operation air conditioner indoor unit is opened, the refrigerating electromagnetic valve is closed, the refrigerating electromagnetic valve corresponding to the refrigerating operation air conditioner indoor unit is opened, the heating electromagnetic valve is closed, and the flow direction of a refrigerant output by the air conditioner outdoor unit is as follows: the high-temperature high-pressure gaseous refrigerant output by the refrigerant output pipe enters the second gas-liquid separator, the high-pressure gaseous refrigerant flowing out of the gas side outlet of the second gas-liquid separator enters the heating inner machine through the heating electromagnetic valve, exchanges heat with the indoor heat exchanger of the heating inner machine and is condensed into high-pressure liquid refrigerant, then the refrigerant is changed into a medium-pressure two-phase refrigerant through an electronic expansion valve of the refrigerant-operated air conditioner, then the refrigerant reaches a main path inlet of a main subcooler through a heating one-way valve corresponding to the refrigerant-operated air conditioner, the refrigerant is changed into a high-pressure liquid refrigerant after being subcooled by the main subcooler, the high-pressure liquid refrigerant is divided into two paths, one path of the refrigerant enters a refrigeration inner machine corresponding to the refrigerant-operated air conditioner through a refrigeration one-way valve corresponding to the refrigeration inner machine, the refrigerant is throttled and depressurized through the electronic expansion valve of the refrigeration inner machine, enters an indoor heat exchanger of the refrigeration inner machine to be evaporated and absorbed to be changed into a medium; the other path of refrigerant supercooled by the main subcooler enters an auxiliary path of the main subcooler after being throttled by the main throttling device, becomes medium-pressure two-phase refrigerant and reaches an outlet of the refrigerant distribution device.

When the main refrigeration operation is performed, the heating electromagnetic valve corresponding to the indoor unit of the air conditioner in the heating operation is opened, the refrigeration electromagnetic valve is closed, the refrigeration electromagnetic valve corresponding to the indoor unit of the air conditioner in the refrigeration operation is opened, the heating electromagnetic valve is closed, and the flow direction of a refrigerant output by the outdoor unit of the air conditioner is as follows: the high-temperature high-pressure liquid refrigerant output by the refrigerant output pipe enters a second gas-liquid separator, the high-pressure gas refrigerant flowing out of a gas side outlet of the second gas-liquid separator enters a heating inner machine through a heating electromagnetic valve corresponding to the heating inner machine, exchanges heat with an indoor heat exchanger of the heating inner machine and then is condensed into the high-pressure liquid refrigerant, the high-pressure liquid refrigerant passes through an inner machine electronic expansion valve to be changed into a medium-pressure two-phase refrigerant, and then the medium-pressure two-phase refrigerant reaches a main path inlet of a main subcooler through a heating one-way valve corresponding to the medium-pressure liquid refrigerant and is converged with the high-pressure liquid refrigerant; the high-pressure liquid refrigerant flowing out of the liquid side outlet of the second gas-liquid separator and the high-pressure liquid refrigerant discharged by the heating indoor unit are converged and then reach the main path inlet of the main subcooler, and after entering the main subcooler for subcooling, the liquid refrigerant flowing out of the main path outlet is divided into two paths, one path of the liquid refrigerant is throttled by the main throttling device and depressurized, and is changed into low-pressure gaseous refrigerant after being absorbed by the auxiliary path of the main subcooler and then reaches the outlet of the refrigerant distribution device; the other path of refrigerant flowing out of the main path outlet enters the refrigerating inner machine through a refrigerating one-way valve corresponding to the refrigerating inner machine, flows through an electronic expansion valve of the refrigerating inner machine for throttling and pressure reduction, then enters an indoor heat exchanger of the refrigerating inner machine for evaporation and heat absorption to be changed into low-pressure gaseous refrigerant, and then reaches the outlet of the refrigerant distribution device through a plurality of refrigerating electromagnetic valves.

In the above technical scheme, the refrigerant distribution device further includes a branch line, one end of the branch line is connected to any node between the outlet of the heating one-way valve and the main path inlet of the main subcooler, the other end of the branch line is connected to the outlet of the refrigerant distribution device, and a third control valve for controlling the on-off of the branch line is arranged on the branch line.

In the refrigerant distribution device, a branch flow path is additionally arranged, one end of the branch flow path is connected to any node between the outlet of the heating one-way valve and the main path inlet of the main subcooler, and the other end of the branch flow path is connected to the outlet of the refrigerant distribution device, so that only one part of the medium-pressure two-phase refrigerant flowing out of the heating one-way valve enters the main subcooler for subcooling, and the other part of the medium-pressure two-phase refrigerant directly reaches the outlet of the refrigerant distribution device through the branch flow path under the conditions of pure heating operation and main heating operation, thereby reducing the pressure loss of the medium-pressure two-phase refrigerant, improving the pressure of the two-phase refrigerant reaching the inlet of the flash evaporator, further improving the air injection enthalpy increasing effect of the compressor, and further improving the low-temperature heating; meanwhile, the noise of the inner machine pipeline can be reduced. Preferably, the third control valve is a solenoid valve.

In the above technical solution, the number of the shunting branches is plural, and the plural shunting branches are connected in parallel.

The quantity of reposition of redundant personnel branch road is a plurality of, and a plurality of reposition of redundant personnel branch roads are parallelly connected in parallel, can further reduce the volume that gets into main subcooler by the double-phase refrigerant of middling pressure that heats the check valve outflow to can further reduce the loss of pressure of the double-phase refrigerant of middling pressure, further improve the pressure that reaches the double-phase refrigerant of flash vessel entrance, and then further improve the jet enthalpy gain effect of compressor, further improve the low temperature and heat the effect.

Preferably, the number of the branch flow paths is two, so that the requirement of enhanced vapor injection is met, and the pipeline layout of the product is simplified.

In the above technical scheme, when the two-pipe heating recovery multi-split air conditioner system operates in a pure heating mode, the control system of the two-pipe heating recovery multi-split air conditioner system controls the opening degree of the main throttling device to be adjusted to the maximum, and controls the third control valve to conduct the branch.

For the conditions of pure heating operation and main heating operation, the opening degree of a main throttling device of the refrigerant distribution device is adjusted to be the largest, and meanwhile, the third control valve is controlled to conduct the branch, so that the flow of the refrigerant entering the main subcooler is reduced, the pressure loss of the refrigerant passing through the main subcooler is reduced, the pressure loss of medium-pressure two-phase refrigerant is further reduced, the pressure of the two-phase refrigerant reaching the inlet of the flash evaporator is further improved, the vapor injection enthalpy increasing effect of the compressor is further improved, and the low-temperature heating effect is further improved.

In any of the above technical solutions, the refrigerant distribution device further includes an auxiliary subcooler and an auxiliary throttling device, the main path of the auxiliary subcooler is disposed between the liquid side outlet of the second gas-liquid separator and the main path inlet of the main subcooler, the auxiliary throttling device is disposed between the main path outlet of the auxiliary subcooler and the main path inlet of the main subcooler, and the auxiliary path of the auxiliary subcooler is disposed between the auxiliary path outlet of the main subcooler and the outlet of the refrigerant distribution device.

An auxiliary subcooler and an auxiliary throttling device are arranged between the second gas-liquid separator and the main subcooler, so that the supercooling degree of the liquid refrigerant output by the main path of the main subcooler can be further improved, and the refrigerating capacity of the system is further improved.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural diagram of a two-pipe heat recovery multi-split air conditioning system according to a first embodiment of the present invention;

fig. 2 is a schematic structural diagram of a two-pipe heat recovery multi-split air conditioning system according to a second embodiment of the present invention;

FIG. 3 is a schematic diagram of the pure heating mode of the two-pipe heat recovery multi-split air conditioning system shown in FIG. 1;

FIG. 4 is a schematic diagram of the two-pipe heat recovery multi-split system of FIG. 1 in a pure cooling mode;

FIG. 5 is a schematic diagram of a main heating mode of the two-pipe heat recovery multi-split air conditioning system shown in FIG. 1;

FIG. 6 is a schematic diagram of the two-pipe heat recovery multi-split air conditioning system of FIG. 1 in a main cooling mode;

fig. 7 is a schematic diagram of a two-pipe heat recovery multi-split air conditioning system according to some embodiments of the present invention.

Wherein, the correspondence between the reference numbers and the part names in fig. 1 to 6 is:

10 compressor, 11 exhaust port, 12 return air port, 13 air jet port, 201 first check valve, 202 second check valve, 203 third check valve, 204 fourth check valve, 205 fifth check valve, 206 sixth check valve, 207 four-way valve, 208 first control valve, 209 second control valve, 30 outdoor heat exchanger, 401 first pipeline, 402 second pipeline, 403 third pipeline, 404 fourth pipeline, 405 fifth pipeline, 406 sixth pipeline, 407 seventh pipeline, 408 eighth pipeline, 409 ninth pipeline, 410 tenth pipeline, 411 refrigerant input pipe, 412 refrigerant output pipe, 50 flash evaporator, 60 outdoor throttling device, 70 first gas-liquid separator, 80 first refrigerant distributing device, 81 second gas-liquid separator, 82 main throttling device, 83 main throttling device, 841 heating solenoid valve, 842 cooling solenoid valve, 843 heating check valve, 844 cooling check valve, 85 auxiliary throttling device, 86 auxiliary throttling device, 87 sub-cooling branch, 88 a third control valve, 90 an indoor unit of an air conditioner, 91 an indoor heat exchanger and 92 an electronic expansion valve.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

A two-pipe heat recovery multi-split air conditioning indoor unit and a two-pipe heat recovery multi-split air conditioning system according to some embodiments of the present invention will be described with reference to fig. 1 to 7.

As shown in fig. 1 and 2, an outdoor unit of an air conditioner according to an embodiment of the first aspect of the present invention is used in a two-pipe heat recovery multiple split system, where the two-pipe heat recovery multiple split system includes a plurality of indoor units 90 and a refrigerant distribution device 80 connecting the outdoor unit and the plurality of indoor units 90, and the outdoor unit includes: a main circulation flow path and an enhanced vapor injection flow path.

Specifically, the main circulation flow path includes the enhanced vapor injection compressor 10, the reversing device and the outdoor heat exchanger 30 connected by pipelines, and two ends of the main circulation flow path are respectively communicated with the inlet and the outlet of the refrigerant distribution device 80 by a refrigerant output pipe 412 (a pipe in the figure) and a refrigerant input pipe 411 (B pipe in the figure); the enhanced vapor injection flow path comprises a flash evaporator 50 and an outdoor throttling device 60, an inlet (a port in the figure) of the flash evaporator 50 is communicated with a refrigerant input pipe 411 through a first pipeline 401, an outlet (b port in the figure) on the gas side of the flash evaporator 50 is connected with an air injection port 13 of the enhanced vapor injection compressor 10 through a second pipeline 402, an outlet (c port in the figure) on the liquid side of the flash evaporator 50 is connected with the input end of the outdoor heat exchanger 30 through a third pipeline 403, and the outdoor throttling device 60 is arranged on the third pipeline 403.

In the air-conditioning outdoor unit for the two-pipe heat recovery multi-split air-conditioning system provided by the embodiment of the first aspect of the invention, the air-injection enthalpy-increasing compressor 10 technology is used, and the flash evaporator 50 and the outdoor throttling device 60 are added, so that an air-injection enthalpy-increasing flow path is added to the air-conditioning outdoor unit, and a heat-injection enthalpy-increasing function is added to the two-pipe heat recovery multi-split air-conditioning system, so that the refrigerant circulation quantity during low-temperature heating operation of the two-pipe heat recovery multi-split air-conditioning system is obviously increased, the low-temperature heating operation range of the two-pipe heat recovery multi-split air-conditioning system is further expanded, and the heating effect of.

Specifically, in the existing two-pipe heat recovery multi-split air-conditioning system, because a return pipe on the outdoor unit side of the air-conditioning unit only has a low-pressure refrigerant and cannot provide a medium-pressure refrigerant for the air injection port 13 of the enhanced vapor injection compressor 10, the enthalpy injection is difficult to realize at the air injection port 13 of the compressor 10, so that the enhanced vapor injection low-temperature forcing technology is only applied to a heat pump and a three-pipe heat recovery system at present, and a two-pipe heat recovery multi-split air-conditioning system with enhanced vapor injection function does not exist; and this application is through improving air condensing units for two pipe heating recovery multi-split air conditioning units system has possessed the enhanced vapor injection function, thereby adopts the enhanced vapor injection technique to realize the breakthrough of two pipe heating recovery multi-split air conditioning units system low temperature intense heat technique's application, has satisfied two pipe heating recovery multi-split air conditioning units system operation requirement under lower outdoor environment temperature, has improved the travelling comfort of heating.

Specifically, the air conditioner outdoor unit comprises a main circulation flow path and an enhanced vapor injection flow path, the main circulation flow path comprises an enhanced vapor injection compressor 10, a reversing device and an outdoor heat exchanger 30 which are connected through pipelines, one end of the main circulation flow path is communicated with an inlet of a refrigerant distribution device 80 through a refrigerant output pipe 412 to convey refrigerant to the refrigerant distribution device 80, the refrigerant distribution device 80 distributes the refrigerant entering and exiting a plurality of air conditioner indoor units 90, and then the refrigerant after heat exchange is sent back to the air conditioner outdoor unit through a refrigerant input pipe 411 to finally complete circulation; in the process of refrigerant flowing, all parts on the main circulation flow path and all parts on the enhanced vapor injection flow path are correspondingly matched, so that the two-pipe heat recovery multi-split air conditioner system realizes the refrigerating and heating functions (such as a pure refrigerating mode, a pure heating mode, a main refrigerating mode, a main heating mode and the like).

Compared with the prior art, the application adds the flash evaporator 50 and the outdoor throttling device 60 in the outdoor unit of the air conditioner, the inlet of the flash evaporator 50 is communicated with the refrigerant input pipe 411 of the outdoor unit of the air conditioner through the first pipeline 401, the outlet at the air side is connected with the air jet 13 of the enhanced vapor injection compressor 10 through the second pipeline 402, the outlet at the liquid side is connected with the input end of the outdoor heat exchanger 30 through the third pipeline 403, and the outdoor throttling device 60 is arranged on the third pipeline 403, so that the refrigerant flowing back to the outdoor unit of the air conditioner from the refrigerant input pipe 411 during the heating operation (including the pure heating mode and the main heating mode) directly flows to the air jet 13 of the compressor 10 after being divided into two paths through the flash evaporator 50, and the liquid refrigerant flowing to the outdoor heat exchanger 30 enters the outdoor heat exchanger 30 to be evaporated and absorb heat and then flows back to the return air port 12 of the compressor 10 after being throttled and depressurized through the outdoor, so that the pressure of the return air port 12 of the compressor 10 is lower than the pressure of the air jet port 13 of the compressor 10, thereby realizing the enhanced vapor injection of the compressor 10. In other words, the present application is equivalent to adding the flash evaporator 50 and the outdoor throttling device 60 to the return pipe (i.e. the refrigerant input pipe 411) of the existing air conditioner outdoor unit, so that at least a part of the throttling function of the system during the heating operation (including the pure heating mode and the main heating mode) is performed at the air conditioner outdoor unit side, and thus the refrigerant pressure at the refrigerant input pipe 411 is higher than the pressure at the outlet of the outdoor heat exchanger 30, and becomes a medium-pressure two-phase refrigerant, rather than a low-pressure refrigerant in the prior art; the medium-pressure two-phase refrigerant is subjected to gas-liquid separation in the flash evaporator 50, the generated medium-pressure gaseous refrigerant enters the gas jet 13 of the compressor 10 for enhanced vapor injection, and the generated medium-pressure liquid refrigerant enters the outdoor heat exchanger 30 for heat exchange after throttling and pressure reduction and flows back to the gas return port 12 of the compressor 10.

It can be understood that the refrigerant input pipe 411 and the refrigerant output pipe 412 are respectively provided with a stop valve, which respectively correspond to a low pressure valve and a high pressure valve in the prior art; in addition, the high-pressure refrigerant, the medium-pressure refrigerant and the low-pressure refrigerant in the application only indicate the relative pressure of the refrigerants at different positions in the refrigerant circulation flow path in the operation process of the air conditioner, and the air conditioner is not limited by specific numerical values.

The following describes the specific structure and operation principle of the outdoor unit of the air conditioner provided by the present application in detail with reference to some embodiments.

Example one

The second pipeline 402 is provided with a first control valve 208 capable of controlling the on-off of the second pipeline, as shown in fig. 1 and 2.

The first control valve 208 is arranged on the second pipeline 402, and the first control valve 208 can control the on-off of the second pipeline 402, so that the selective on-off of the second pipeline 402 is realized, and thus, under the condition that the system does not need enthalpy injection and air supplement, such as refrigeration operation, the second pipeline 402 can be disconnected through the first control valve 208, and other functions (such as a pure refrigeration mode and a main refrigeration mode) of the system are prevented from being influenced, so that the reliability of the system is improved.

Preferably, the first control valve 208 is a solenoid valve.

The electromagnetic valve is used as the first control valve 208, so that the on-off of the second pipeline 402 can be effectively controlled, and the automatic control of the system can be realized conveniently. Of course, the first control valve 208 is not limited to a solenoid valve, and may be other types of valves as long as the second pipeline 402 can be controlled to be opened or closed.

Further, the third pipeline 403 is further provided with a first check valve 201, and the first check valve 201 is in one-way communication in a direction from the liquid side outlet of the flash evaporator 50 to the input end of the outdoor heat exchanger 30 of the outdoor throttling device 60, as shown in fig. 1 and 2.

The first check valve 201 is arranged on the third pipeline 403, and the first check valve 201 is in one-way conduction in the direction from the liquid side outlet of the flash evaporator 50 to the input end of the outdoor heat exchanger 30, so that only the liquid refrigerant output by the flash evaporator 50 can flow to the outdoor throttling device 60 and the outdoor heat exchanger 30 in sequence and cannot flow in the reverse direction, and thus, the outdoor throttling device 60 only plays a role in throttling and pressure reducing during heating operation; and the high-pressure refrigerant discharged from the compressor 10 during the refrigeration operation can only flow to the outdoor heat exchanger 30, but cannot flow to the flash evaporator 50 through the outdoor throttling device 60, which causes unnecessary pressure loss or gas leakage and other undesirable phenomena, thereby ensuring the normal operation of the refrigeration function of the system.

Further, a first one-way valve 201 is located between the liquid side outlet of the flash evaporator 50 and the outdoor throttling device 60, as shown in fig. 1 and 2.

The first check valve 201 is arranged between the liquid side outlet of the flash evaporator 50 and the outdoor throttling device 60, so that the refrigerant can only flow to the outdoor throttling device 60 from the liquid side outlet of the flash evaporator 50 and can not flow reversely, and the influence on the energy efficiency of the system caused by unnecessary pressure loss or air leakage and the like due to the fact that the high-pressure refrigerant discharged from the compressor 10 enters the outdoor throttling device 60 is further prevented.

Further, as shown in fig. 1 and fig. 2, the reversing device includes a four-way valve 207, a second one-way valve 202, a third one-way valve 203, a fourth one-way valve 204, a fifth one-way valve 205 and a sixth one-way valve 206, a first port of the four-way valve 207 is communicated with the exhaust port 11 of the enhanced vapor injection compressor 10 through a fourth pipeline 404, a second port of the four-way valve 207 is respectively connected with the input end and the output end of the outdoor heat exchanger 30 through a fifth pipeline 405 and a sixth pipeline 406, a third port of the four-way valve 207 is respectively communicated with the refrigerant input pipe 411 and the refrigerant output pipe 412 through a seventh pipeline 407 and an eighth pipeline 408, a fourth port of the four-way valve 207 is communicated with the return air port 12 of the enhanced vapor injection compressor 10 through a ninth pipeline 409, and an output end of the outdoor heat exchanger 30 is further communicated with the refrigerant output; the second check valve 202 is disposed on the fifth pipeline 405, and is in one-way communication in a direction from the second port to the input end of the outdoor heat exchanger 30; the third check valve 203 is arranged on the sixth pipeline 406 and is communicated in a one-way mode in a direction from the output end of the outdoor heat exchanger 30 to the second port; the fourth check valve 204 is disposed on the seventh pipeline 407, and is communicated in a one-way manner in a direction from the refrigerant input pipe 411 to the third port; the fifth check valve 205 is disposed on the eighth pipeline 408 and is in one-way communication in a direction from the third port to the refrigerant output pipe 412; the sixth check valve 206 is disposed on the tenth pipe 410 and is in one-way communication in a direction from the output end of the outdoor heat exchanger 30 to the refrigerant output pipe 412.

The reversing device comprises a four-way valve 207 and a plurality of one-way valves, the four-way valve 207 is matched with the one-way valves, the functions of selective on-off and one-way conduction of all pipelines of the outdoor unit of the air conditioner are achieved, and further the normal implementation of all functions of pure refrigeration, pure heating, main heating and the like of the system is guaranteed.

When the pure heating operation is performed, the first port of the four-way valve 207 is communicated with the third port, the second port is communicated with the fourth port, the first control valve 208 is opened, as shown in fig. 3, the refrigerant flow direction of the system is as follows: the high-temperature and high-pressure gaseous refrigerant is discharged from the exhaust port 11 of the enhanced vapor injection compressor 10, reaches the first port of the four-way valve 207 through the fourth pipeline 404, flows out of the third port of the four-way valve 207, and reaches the refrigerant output pipe 412 through the eighth pipeline 408 and the fifth check valve 205; then the refrigerant enters each air conditioner indoor unit 90 for condensation and heat release after entering the refrigerant distribution device 80 for distribution, and then is changed into a medium-pressure two-phase refrigerant by the refrigerant distribution device 80 to reach the refrigerant input pipe 411; the medium-pressure two-phase refrigerant reaches an inlet of the flash evaporator 50 through a first pipeline 401, is separated in the flash evaporator 50, is discharged from a gas side outlet, reaches an air jet 13 of the compressor 10 through a second pipeline 402 and a first control valve 208, and enters a compression cavity of the compressor 10; the generated medium-pressure liquid refrigerant is discharged from the liquid-side outlet, reaches the outdoor throttling device 60 through the third pipeline 403 and the first check valve 201, is throttled and depressurized, then enters the outdoor heat exchanger 30 to be evaporated and absorbed, becomes a low-pressure gaseous refrigerant, then reaches the second port of the four-way valve 207 through the sixth pipeline 406 and the third check valve 203, flows out from the fourth port of the four-way valve 207, and returns to the return port 12 of the compressor 10 through the ninth pipeline 409.

During pure refrigeration operation, the first port and the second port of the four-way valve 207 are communicated, the third port and the fourth port are communicated, the first control valve 208 is closed, and as shown in fig. 4, the refrigerant flow direction of the system is as follows: the high-temperature and high-pressure gaseous refrigerant is discharged from the exhaust port 11 of the enhanced vapor injection compressor 10, reaches the first port of the four-way valve 207 through the fourth pipeline 404, flows out of the second port of the four-way valve 207, enters the outdoor heat exchanger 30 through the fifth pipeline 405 and the second one-way valve 202, is condensed and released in the outdoor heat exchanger 30 to become a high-temperature and high-pressure liquid refrigerant, and reaches the refrigerant output pipe 412 through the tenth pipeline 410 and the sixth one-way valve 206; then enters the refrigerant distribution device 80 to be distributed, enters each air conditioner indoor unit 90 to be evaporated and absorb heat to be changed into low-pressure gaseous refrigerant, and then reaches the refrigerant input pipe 411 through the refrigerant distribution device 80; the low-pressure gaseous refrigerant reaches the third port of the four-way valve 207 through the seventh conduit 407 and the fourth check valve 204, flows out of the fourth port of the four-way valve 207, and returns to the return port 12 of the compressor 10 through the ninth conduit 409.

During the main heating operation, the first port of the four-way valve 207 is communicated with the third port, the second port is communicated with the fourth port, the first control valve 208 is opened, as shown in fig. 5, the refrigerant flow direction of the system is: the high-temperature and high-pressure gaseous refrigerant is discharged from the exhaust port 11 of the enhanced vapor injection compressor 10, reaches the first port of the four-way valve 207 through the fourth pipeline 404, flows out of the third port of the four-way valve 207, and reaches the refrigerant output pipe 412 through the eighth pipeline 408 and the fifth check valve 205; then the refrigerant enters the refrigerant distribution device 80 to be distributed and then enters the air conditioner indoor unit 90 in heating operation to be condensed and released heat to be changed into a medium-pressure two-phase refrigerant, the medium-pressure two-phase refrigerant enters the refrigerant distribution device 80 to be divided into two paths after being supercooled, one path of the refrigerant can flow to the outlet of the refrigerant distribution device 80 through a throttling element, the other path of the refrigerant can enter the air conditioner indoor unit 90 in cooling operation to be evaporated and absorbed heat to be changed into a low-pressure gaseous refrigerant and then reach the outlet of the refrigerant distribution device 80, and the two paths of the refrigerant reach the refrigerant input pipe 411 in a medium; then, the medium-pressure two-phase refrigerant reaches an inlet of the flash evaporator 50 through a first pipeline 401, is separated in the flash evaporator 50, is discharged from a gas side outlet, reaches an air jet 13 of the compressor 10 through a second pipeline 402 and a first control valve 208, and enters a compression cavity of the compressor 10; the generated medium-pressure liquid refrigerant is discharged from the liquid-side outlet, reaches the outdoor throttling device 60 through the third pipeline 403 and the first check valve 201, is throttled and depressurized, is changed into a low-pressure refrigerant, then enters the outdoor heat exchanger 30, is evaporated and absorbed to be changed into a low-pressure gaseous refrigerant, then reaches the second port of the four-way valve 207 through the sixth pipeline 406 and the third check valve 203, flows out of the fourth port of the four-way valve 207, and returns to the return port 12 of the compressor 10 through the ninth pipeline 409.

During the main cooling operation, the first port and the second port of the four-way valve 207 are communicated, the third port and the fourth port are communicated, the first control valve 208 is closed, as shown in fig. 6, the refrigerant flow direction of the system is: the high-temperature and high-pressure gaseous refrigerant is discharged from the exhaust port 11 of the enhanced vapor injection compressor 10, reaches the first port of the four-way valve 207 through the fourth pipeline 404, flows out of the second port of the four-way valve 207, enters the outdoor heat exchanger 30 through the fifth pipeline 405 and the second one-way valve 202, is condensed and released in the outdoor heat exchanger 30 to become a high-temperature and high-pressure liquid refrigerant, and reaches the refrigerant output pipe 412 through the tenth pipeline 410 and the sixth one-way valve 206; after the refrigerant entering the refrigerant distribution device 80 is subjected to gas-liquid separation, the separated liquid refrigerant is throttled and depressurized, enters the air conditioner indoor unit 90 in the cooling operation to be evaporated and absorb heat to be changed into a low-pressure gaseous refrigerant, and reaches the outlet of the refrigerant distribution device 80, the separated gaseous refrigerant enters the air conditioner indoor unit 90 in the heating operation to be condensed and release heat, returns to the refrigerant distribution device 80 to be supercooled, then enters the cooling indoor unit to be evaporated and absorb heat to be changed into a low-pressure gaseous refrigerant, and reaches the outlet of the refrigerant distribution device 80, and the two paths of low-pressure gaseous refrigerants are converged; the low-pressure gaseous refrigerant then passes through the seventh conduit 407 and the fourth check valve 204 to the third port of the four-way valve 207, exits the fourth port of the four-way valve 207, and returns to the return port 12 of the compressor 10 through the ninth conduit 409.

Further, the outlet of the second check valve 202 is located between the outdoor throttling device 60 and the input of the outdoor heat exchanger 30, as shown in fig. 1 and 2.

The outlet of the second check valve 202 is arranged between the outdoor throttling device 60 and the input end of the outdoor heat exchanger 30, so that the high-temperature and high-pressure refrigerant discharged by the compressor 10 during the refrigeration operation can not enter the outdoor heat exchanger 30 through the outdoor throttling device 60, unnecessary pressure loss is avoided, and the refrigeration capacity of the system is improved.

Further, a first gas-liquid separator 70 is disposed on the ninth pipeline 409, as shown in fig. 1 and 2.

The ninth pipeline 409 is provided with the first gas-liquid separator 70, which can perform gas-liquid separation on the refrigerant flowing back to the return air port 12 of the compressor 10, so as to prevent the liquid refrigerant from flowing back to the return air port 12 of the compressor 10 to generate liquid impact, thereby improving the use reliability of the compressor 10.

Further, the reversing device further includes a second control valve 209, as shown in fig. 1 and fig. 2, two ends of the second control valve 209 are respectively communicated with the exhaust port 11 and the refrigerant output pipe 412, and the second control valve 209 is in a closed state in the pure cooling mode.

The reversing device further comprises a second control valve 209, two ends of the second control valve 209 are respectively communicated with the exhaust port 11 of the compressor 10 and the refrigerant output pipe 412, and the second control valve 209 is in a closed state in the pure cooling mode, so that under the condition of heating operation (namely pure heating operation, main heating operation and main cooling operation) of at least part of the air-conditioning indoor units 90, one part of high-temperature and high-pressure gaseous refrigerant exhausted from the exhaust port 11 of the compressor 10 can directly enter the refrigerant distribution device 80 by opening the second control valve 209 and then enter the heating indoor units for condensation and heat release, thereby reducing pressure loss in the process that the high-temperature and high-pressure gaseous refrigerant reaches the heating indoor units, improving the heating capacity of the system, and ensuring the realization of functions of main cooling and the like of the system. Preferably, the second control valve is a solenoid valve.

Specifically, for the pure heating operation and the main heating operation, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 10 is divided into two paths, and the two paths enter the refrigerant distribution device 80 through the four-way valve 207 and the second control valve 209, as shown in fig. 3 and 5, which is equivalent to increasing the flow area of the high-temperature and high-pressure gaseous refrigerant, thereby reducing the pressure loss of the high-temperature and high-pressure refrigerant at the outdoor side; for the main refrigeration operation, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 10 is also divided into two paths, one path enters the outdoor heat exchanger 30 through the four-way valve 207 to be condensed and released to become a liquid refrigerant, and then reaches the refrigerant output pipe 412, as shown in fig. 6, the other path reaches the refrigerant output pipe 412 through the second control valve 209, and the two paths of refrigerants are mixed into a two-phase refrigerant and enter the refrigerant distribution device 80; the liquid refrigerant after gas-liquid separation enters the refrigerating inner machine for evaporation and heat absorption, the gas refrigerant after gas-liquid separation enters the heating inner machine for condensation and heat release, the liquid refrigerant after heat exchange can also enter the refrigerating inner machine for heat exchange after being supercooled by the refrigerant distribution device 80, and the pressure loss of the refrigerant entering the heating inner machine is reduced because the refrigerant entering the heating inner machine does not pass through the throttling function of the throttling device and the like.

Of course, the second control valve may not be provided, and the main refrigeration operation can also be realized by heating the refrigerant after the heat exchange of the refrigeration indoor unit and then sending the refrigerant into the second gas-liquid separator, or directly sending the refrigerant into the heating indoor unit for condensation and heat release.

Specifically, the outdoor throttling device 60 includes a throttling element, as shown in fig. 1 and 2.

Example two

The difference from the first embodiment is that: the outdoor restriction 60 comprises a plurality of parallel connected restriction elements.

EXAMPLE III

The difference from the first embodiment is that: the outdoor throttle 60 includes at least one throttle element and a shunt solenoid valve connected in parallel.

The outdoor throttling device 60 mainly performs a throttling and pressure reducing function, and the specific form thereof is not limited. Such as: the refrigerant throttling device can only comprise one throttling element, also can comprise a plurality of throttling elements connected in parallel, also can be a parallel combination of the throttling element and a flow dividing electromagnetic valve (namely, the electromagnetic valve playing a flow dividing role and preventing all refrigerants from entering the throttling element), and the like, and also can be in other forms; the forms of the throttling elements are not limited, such as capillary tubes, electronic expansion valves 92 and the like, which are not listed, and since the throttling and pressure reducing functions can be realized without departing from the design concept and the purpose of the invention, the throttling and pressure reducing functions are all within the protection scope of the invention, and the specific forms and the number can be reasonably adjusted according to the specific structure and the requirements of products in the actual production process.

As shown in fig. 1 and fig. 2, an embodiment of the second aspect of the present invention provides a two-pipe heat recovery multi-split air-conditioning system, including: the outdoor unit of an air conditioner, the plurality of indoor units 90 of an air conditioner, and the refrigerant distribution device 80 according to any one of the first to third embodiments.

Specifically, a plurality of air conditioning indoor units 90 are connected in parallel; the refrigerant distribution device 80 is disposed between the outdoor unit and the indoor units 90, and is configured to connect the outdoor unit and the indoor units 90, and distribute the refrigerant entering and exiting the indoor units 90.

The two-pipe heating recovery multi-split air conditioner system provided by the embodiment of the second aspect of the present invention includes the outdoor unit of the air conditioner of any one of the embodiments of the first aspect, so that all the advantages of any one of the embodiments are provided, and details are not repeated herein.

The following describes the specific structure and operation principle of the two-pipe heat recovery multi-split air conditioning system provided by the present application in detail with reference to some embodiments.

Example one

The refrigerant distribution device 80 includes a second gas-liquid separator 81, a main subcooler 82, a main throttling device 83, a plurality of refrigeration check valves 844, a plurality of heating check valves 843, a plurality of refrigeration solenoid valves 842 and a plurality of heating solenoid valves 841 connected through a pipeline; wherein, the inlet of the second gas-liquid separator 81 is communicated with the inlet of the refrigerant distributor device, the liquid side outlet of the second gas-liquid separator 81 is connected to the main path inlet of the main subcooler 82 through a pipeline, the main throttling device 83 is arranged between the main path outlet of the main subcooler 82 and the auxiliary path inlet of the main subcooler 82, and the auxiliary path outlet of the main subcooler 82 is connected to the outlet of the refrigerant distributor device 80 through a pipeline; the gas-side outlet of the second gas-liquid separator 81 is connected to the first ends of the plurality of air-conditioning indoor units 90 through the plurality of heating solenoid valves 841, respectively, the second ends of the plurality of air-conditioning indoor units 90 are connected to the main path inlet of the main subcooler 82 through the plurality of heating check valves 843, respectively, and the plurality of heating check valves 843 are communicated in a unidirectional manner in a direction from the second ends of the plurality of air-conditioning indoor units 90 to the main path inlet of the main subcooler 82; a main path outlet of the main subcooler 82 is connected to the second ends of the air-conditioning indoor units 90 through a plurality of refrigeration check valves 844, and the plurality of refrigeration check valves 844 are conducted in a single direction from the main path outlet of the main subcooler 82 to the second ends of the air-conditioning indoor units 90; first ends of the indoor air conditioners 90 are connected to outlets of the refrigerant distribution device 80 through a plurality of refrigeration solenoid valves 842, as shown in fig. 1 and 2.

The refrigerant distribution device 80 includes a second gas-liquid separator 81, a main subcooler 82, a main throttling device 83, a plurality of heating solenoid valves 841, a plurality of refrigerating solenoid valves 842, a plurality of heating check valves 843 and a plurality of refrigerating check valves 844, which are matched with each other, so as to realize the functions of selective on-off and one-way conduction of each pipeline in the refrigerant distribution device 80 and each air-conditioning indoor unit 90, and further ensure the normal realization of each function of system refrigeration, heating, and the like.

In the pure heating operation, the plurality of heating solenoid valves 841 are opened, the plurality of cooling solenoid valves 842 are closed, and as shown in fig. 3, the flow direction of the refrigerant output by the outdoor unit of the air conditioner is: the high-temperature and high-pressure gaseous refrigerant output by the refrigerant output pipe 412 enters the second gas-liquid separator 81, the high-pressure gaseous refrigerant flowing out of the gas side outlet of the second gas-liquid separator 81 enters the plurality of air-conditioning indoor units 90 through the plurality of heating electromagnetic valves 841, exchanges heat with the indoor heat exchangers 91 of the air-conditioning indoor units 90, is condensed into high-pressure liquid refrigerant, and then passes through the indoor unit electronic expansion valve 92 to become medium-pressure two-phase refrigerant; and then reaches the main path inlet of the main subcooler 82 of the refrigerant distribution device 80 through the heating check valves 843, enters the main subcooler 82 for subcooling, flows out of the main path outlet, then reaches the outlet of the refrigerant distribution device 80 through the main throttling device 83 and the auxiliary path of the main subcooler 82, and returns to the refrigerant input pipe 411 of the air conditioning outdoor unit. In this process, the opening degree of the main throttling device 83 is maintained fully opened to reduce the resistance as much as possible, reduce the pressure loss of the medium-pressure two-phase refrigerant as much as possible, and ensure that the pressure of the two-phase refrigerant reaching the flash evaporator 50 is enough to realize the subsequent enhanced vapor injection.

When the air conditioner is running in pure cooling mode, the plurality of cooling solenoid valves 842 are opened, the plurality of heating solenoid valves 841 are closed, and as shown in fig. 4, the flow direction of the refrigerant output by the outdoor unit of the air conditioner is: the high-temperature high-pressure liquid refrigerant output by the refrigerant output pipe 412 enters the second gas-liquid separator 81, the high-pressure liquid refrigerant flowing out of the liquid side outlet of the second gas-liquid separator 81 reaches the main path inlet of the main subcooler 82, enters the main subcooler 82 for subcooling, the liquid refrigerant flowing out of the main path outlet is divided into two paths, one path is throttled and depressurized by the main throttling device 83, absorbs heat by the auxiliary path of the main subcooler 82, is changed into low-pressure gas refrigerant, and reaches the outlet of the refrigerant distribution device 80; the other path of refrigerant flowing out from the main path outlet enters a plurality of air conditioner indoor units 90 through a plurality of refrigeration one-way valves 844, flows through an indoor unit electronic expansion valve 92 for throttling and pressure reduction, then enters an indoor heat exchanger 91 for evaporation and heat absorption to be changed into low-pressure gaseous refrigerant, and then reaches the outlet of the refrigerant distribution device 80 through a plurality of refrigeration electromagnetic valves 842.

During the main heating operation, the heating solenoid valve 841 corresponding to the indoor unit 90 of the heating operation air conditioner is opened, the cooling solenoid valve 842 is closed, the cooling solenoid valve 842 corresponding to the indoor unit 90 of the cooling operation air conditioner is opened, the heating solenoid valve 841 is closed, as shown in fig. 5, the flow direction of the refrigerant output by the outdoor unit of the air conditioner is: the high-temperature and high-pressure gaseous refrigerant output by the refrigerant output pipe 412 enters the second gas-liquid separator 81, the high-pressure gaseous refrigerant flowing out of the gas-side outlet of the second gas-liquid separator 81 enters the heating inner unit through the heating electromagnetic valve 841, exchanges heat with the indoor heat exchanger 91 of the heating inner unit and is condensed into high-pressure liquid refrigerant, then the refrigerant is changed into a medium-pressure two-phase refrigerant through an electronic expansion valve 92 of the internal machine, then the refrigerant reaches a main path inlet of the main subcooler 82 through a heating one-way valve 843 corresponding to the refrigerant, the refrigerant is subcooled by the main subcooler 82 and then is changed into a high-pressure liquid refrigerant, the high-pressure liquid refrigerant is divided into two paths, one path of the refrigerant enters the corresponding refrigerating internal machine through a refrigerating one-way valve 844 corresponding to the refrigerating operation air-conditioning indoor machine 90, the refrigerant is throttled and depressurized through the electronic expansion valve 92 of the refrigerating internal machine and then enters an indoor heat exchanger 91 of the refrigerating internal machine to be evaporated and absorb heat, then reaches the outlet of the refrigerant distribution device 80 through the corresponding refrigeration solenoid valve 842; the other path of refrigerant supercooled by the main subcooler 82 is throttled by the main throttling device 83 and enters the auxiliary path of the main subcooler 82, becomes medium-pressure two-phase refrigerant and reaches the outlet of the refrigerant distribution device 80.

During the main cooling operation, the heating solenoid valve 841 corresponding to the indoor unit 90 of the cooling operation air conditioner is opened, the cooling solenoid valve 842 is closed, the cooling solenoid valve 842 corresponding to the indoor unit 90 of the cooling operation air conditioner is opened, the heating solenoid valve 841 is closed, as shown in fig. 6, the flow direction of the refrigerant output by the outdoor unit of the air conditioner is: the high-temperature high-pressure liquid refrigerant output by the refrigerant output pipe 412 enters the second gas-liquid separator 81, the high-pressure gas refrigerant flowing out of the gas side outlet of the second gas-liquid separator 81 enters the heating internal unit through the heating electromagnetic valve 841 corresponding to the heating internal unit, exchanges heat with the indoor heat exchanger 91 of the heating internal unit, condenses into the high-pressure liquid refrigerant, then changes into the medium-pressure two-phase refrigerant through the internal electronic expansion valve 92, then reaches the main path inlet of the main subcooler 82 through the heating one-way valve 843 corresponding to the medium-pressure two-phase refrigerant, and joins with the high-pressure liquid refrigerant flowing out of the liquid side outlet of the second gas-liquid separator 81; the high-pressure liquid refrigerant flowing out of the liquid side outlet of the second gas-liquid separator 81 and the high-pressure liquid refrigerant discharged from the heating indoor unit are merged and then reach the main path inlet of the main subcooler 82, the liquid refrigerant flowing out of the main path outlet is divided into two paths after entering the main subcooler 82 for subcooling, one path of the liquid refrigerant is throttled by the main throttling device 83, depressurized, absorbed by the auxiliary path of the main subcooler 82, changed into low-pressure gas refrigerant after being changed into low-pressure gas refrigerant, and then reaches the outlet of the refrigerant distribution device 80; the other path of refrigerant flowing out from the main path outlet enters the refrigeration indoor unit through a refrigeration one-way valve 844 corresponding to the refrigeration indoor unit, flows through an electronic expansion valve 92 of the refrigeration indoor unit for throttling and pressure reduction, then enters an indoor heat exchanger 91 of the refrigeration indoor unit for evaporation and heat absorption to be changed into low-pressure gaseous refrigerant, and then reaches the outlet of the refrigerant distribution device 80 through a plurality of refrigeration solenoid valves 842.

Further, the refrigerant distribution device 80 further includes an auxiliary subcooler 85 and an auxiliary throttling device 86, a main path of the auxiliary subcooler 85 is disposed between a liquid side outlet of the second gas-liquid separator 81 and a main path inlet of the main subcooler 82, the auxiliary throttling device 86 is disposed between a main path outlet of the auxiliary subcooler 85 and a main path inlet of the main subcooler 82, and an auxiliary path of the auxiliary subcooler 85 is disposed between an auxiliary path outlet of the main subcooler 82 and an outlet of the refrigerant distribution device 80, as shown in fig. 1 and 2.

An auxiliary subcooler 85 and an auxiliary throttling device 86 are arranged between the second gas-liquid separator 81 and the main subcooler 82, so that the supercooling degree of the liquid refrigerant output by the main path of the main subcooler 82 can be further improved, and the refrigerating capacity of the system can be further improved.

The main throttling device 83 and the auxiliary throttling device 86 also mainly play a role in throttling and depressurizing, and the specific form is not limited. Such as: the refrigerant throttling device can only comprise one throttling element, also can comprise a plurality of throttling elements connected in parallel, also can be a parallel combination of the throttling element and a flow dividing electromagnetic valve (namely, the electromagnetic valve playing a flow dividing role and preventing all refrigerants from entering the throttling element), and the like, and also can be in other forms; the forms of the throttling elements are not limited, such as capillary tubes, electronic expansion valves 92 and the like, which are not listed, and since the throttling and pressure reducing functions can be realized without departing from the design concept and the purpose of the invention, the throttling and pressure reducing functions are all within the protection scope of the invention, and the specific forms and the number can be reasonably adjusted according to the specific structure and the requirements of products in the actual production process.

Example two

The difference from the first embodiment is that: on the basis of the first embodiment, further, the refrigerant distribution device 80 further includes a branch line 87, one end of the branch line 87 is connected to any node between the outlet of the heating check valve 843 and the main path inlet of the main subcooler 82, the other end of the branch line 87 is connected to the outlet of the refrigerant distribution device 80, and a third control valve 88 for controlling on-off of the branch line 87 is arranged on the branch line 87, as shown in fig. 2.

A branch line 87 is additionally arranged in the refrigerant distribution device 80, one end of the branch line 87 is connected to any node between the outlet of the heating one-way valve 843 and the main path inlet of the main subcooler 82, and the other end of the branch line 87 is connected to the outlet of the refrigerant distribution device 80, so that for the conditions of pure heating operation and main heating operation, only one part of the medium-pressure two-phase refrigerant flowing out of the heating one-way valve 843 enters the main subcooler 82 for subcooling, and the other part of the medium-pressure two-phase refrigerant directly reaches the outlet of the refrigerant distribution device 80 through the branch line 87, so that the pressure loss of the medium-pressure two-phase refrigerant can be reduced, the pressure of the two-phase refrigerant reaching the inlet of the flash evaporator 50 is improved, the vapor injection enthalpy increasing effect of the compressor 10 is further improved, and the low-; meanwhile, the noise of the inner machine pipeline can be reduced. Preferably, the third control valve is a solenoid valve.

Further, the number of the branch lines 87 is plural, and the plural branch lines 87 are connected in parallel, as shown in fig. 2.

The number of the branch lines 87 is multiple, and the branch lines 87 are connected in parallel, so that the amount of the medium-pressure two-phase refrigerant flowing out of the heating one-way valve 843 and entering the main subcooler 82 can be further reduced, the pressure loss of the medium-pressure two-phase refrigerant can be further reduced, the pressure of the two-phase refrigerant reaching the inlet of the flash evaporator 50 can be further increased, the enhanced vapor injection effect of the compressor 10 can be further improved, and the low-temperature heating effect can be further improved.

Preferably, the number of the branch lines 87 is two, as shown in fig. 2, so as to satisfy the requirement of enhanced vapor injection and simplify the pipeline layout of the product.

When the two-pipe heating recovery multi-split air-conditioning system operates in the pure heating mode, the control system of the two-pipe heating recovery multi-split air-conditioning system controls the opening degree of the main throttling device 83 to be adjusted to the maximum, and controls the third control valve 88 to conduct the branch 87.

For the pure heating operation, the opening degree of the main throttling device 83 of the refrigerant distribution device 80 is adjusted to be maximum, and the third control valve 88 is controlled to conduct the branch line 87, so that the flow rate of the refrigerant entering the main subcooler 82 is reduced, the pressure loss of the refrigerant passing through the main subcooler 82 is reduced, the pressure loss of the medium-pressure two-phase refrigerant is further reduced, the pressure of the two-phase refrigerant reaching the inlet of the flash evaporator 50 is further improved, the vapor injection enthalpy increasing effect of the compressor 10 is further improved, and the low-temperature heating effect is further improved.

The working principle of the two-pipe heat recovery multi-split air conditioning system of the present application for low-temperature heating using enhanced vapor injection technology in the pure heating mode and the main heating mode will be described in detail below with reference to the specific embodiment shown in fig. 1.

During heating, as shown in fig. 3, a high-temperature and high-pressure gas refrigerant comes out of the compressor, passes through two paths of solenoid valve SV6 (i.e. a second control valve), four-way valve ST1 and one-way valve DXF-15 (i.e. a fifth one-way valve) to the high-pressure valve, then flows from the high-pressure valve to an MS inlet (i.e. an inlet of a refrigerant distributor) through a high-pressure pipe a (i.e. a refrigerant output pipe), enters a (second) gas-liquid separator, enters an internal machine from a gas pipe through a heating solenoid valve from a gas-liquid outlet of the (second) gas-liquid separator, flows through an electronic expansion valve of the internal machine after being condensed into a high-pressure liquid refrigerant, becomes a high-pressure two-phase refrigerant, flows through a throttling element (i.e. a main throttling device of the MS, the opening degree is maintained fully open, resistance is reduced as much as possible), returns to a low-pressure pipe B (i.e, the refrigerant which is changed into low-pressure two-phase refrigerant by an external machine main throttling element EXVB (namely an outdoor throttling device) enters an external heat exchanger for absorbing heat, then returns to a low-pressure tank (namely a first gas-liquid separator) through a four-way valve ST1 and then enters a compressor return air port; another part of the gaseous refrigerant enters the compression chamber of the compressor through a solenoid valve SV8 (i.e., a first control valve).

During main heating, as shown in fig. 5, the high-temperature and high-pressure gas refrigerant flows out of the compressor, passes through two paths of solenoid valve SV6 (i.e., the second control valve), four-way valve ST1 and check valve DXF-15 (i.e., the fifth check valve) to the high-pressure valve, flows from the high-pressure valve to the MS inlet (i.e., the inlet of the refrigerant distribution device) through the high-pressure pipe a (i.e., the refrigerant output pipe), and enters the (second) gas-liquid separator. High-pressure gaseous refrigerant enters the heating internal machine from a gas-side outlet of the (second) gas-liquid separator through a heating electromagnetic valve from a gas pipe, the condensed high-pressure liquid refrigerant flows back to an inlet of the MS second subcooler (namely a main path inlet of the main subcooler) through an internal machine electronic expansion valve, is changed into high-pressure liquid refrigerant after coming out of the second subcooler (namely a main path of the main subcooler), enters the refrigerating internal machine through a refrigerating one-way valve, is changed into medium-pressure two-phase refrigerant after being throttled by the electronic expansion valve, enters the internal machine for evaporation and heat absorption, is changed into medium-pressure gaseous refrigerant, is converged with the medium-pressure two-phase refrigerant flowing through an MS throttling element (namely a main throttling device) in a low-pressure pipe B (namely a; the refrigerant enters an opening a of an outdoor unit flash evaporator through a check valve DXF-9 (namely a first check valve), medium-pressure refrigerant flowing out of an outlet b at the gas side of the outdoor unit flash evaporator enters a compression cavity of a compressor through an electromagnetic valve SV8 (namely a first control valve), the other part of liquid refrigerant is throttled and decompressed through a main throttling element (EXVA and SV1 (namely an outdoor throttling device)) and enters an external heat exchanger for evaporation and heat exchange, then flows through a four-way valve ST1 to enter a low-pressure tank (namely a first gas-liquid separator), and then returns to a suction port of the compressor.

Further, the explanation is made in conjunction with the enthalpy pressure map shown in fig. 7. Wherein, under the same conditions and frequency, the ordinary refrigeration cycle is: A-E ' -F ' -J ' -A; the main path cycle of the enhanced vapor injection system with the flash evaporator is as follows: A-B-D-E-F-G-H-I-J-J' -A (main loop cycle), and the enthalpy injection flow path cycle is as follows: C-D-E-F-G-H-C.

Specifically, the refrigerant state at the inlet of the flash evaporator is a two-phase state, as shown by a point H, the state point of the gaseous refrigerant discharged from the outlet b at the gas side of the flash evaporator is a point C, and the gaseous refrigerant is continuously compressed after being sprayed into a compression cavity of the compressor; the state point of the liquid refrigerant outlet discharged from the liquid side outlet c of the flash evaporator is point I, the state after throttling and pressure reduction by an outdoor throttling device (EXVB) is point J, and the liquid refrigerant is sucked into a low-pressure cavity of the compressor after absorbing heat by an outdoor heat exchanger to reach an overheat state A. It can be seen from the figure that the enthalpy spraying system with the flash evaporator can increase the circulation volume of the refrigerant (the refrigerant sprayed into the compressor from the gas injection port C is a medium-pressure refrigerant, the density of the refrigerant is much higher than that of the refrigerant at the point A of the return air port, so that the circulation volume of the refrigerant is greatly increased), improve the enthalpy difference of the inlet and the outlet of the outer heat exchanger to improve the heat absorption capacity, reduce the exhaust superheat degree (SH < SH'), increase the pressure ratio, improve the work of the compressor and further improve the heating capacity.

In summary, according to the air-conditioning outdoor unit for the two-pipe heat recovery multi-split air-conditioning system provided by the invention, the air-injection enthalpy-increasing flow path is added to the air-conditioning outdoor unit by using the technology of the air-injection enthalpy-increasing compressor and adding the flash evaporator and the outdoor throttling device, so that the two-pipe heat recovery multi-split air-conditioning system is added with the function of heating air-injection enthalpy-increasing, the refrigerant circulation quantity during the low-temperature heating operation of the two-pipe heat recovery multi-split air-conditioning system is obviously increased, the range of the low-temperature heating operation of the two-pipe heat recovery multi-split air-conditioning system is further expanded, and the heating effect.

In the present invention, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more unless expressly limited otherwise. The terms "mounted," "connected," "fixed," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a removable connection, or an integral connection; "coupled" may be direct or indirect through an intermediary. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "front", "rear", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or unit must have a specific direction, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description herein, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An outdoor unit of an air conditioner, which is used for a two-pipe heating recovery multi-split air conditioner system, wherein the two-pipe heating recovery multi-split air conditioner system comprises a plurality of indoor units of the air conditioner and a refrigerant distribution device for connecting the outdoor unit of the air conditioner with the plurality of indoor units of the air conditioner, and the outdoor unit of the air conditioner comprises:

the main circulation flow path comprises an enhanced vapor injection compressor, a reversing device and an outdoor heat exchanger which are connected through pipelines, and two ends of the main circulation flow path are respectively communicated with an inlet and an outlet of the refrigerant distribution device through a refrigerant output pipe and a refrigerant input pipe; and

the enhanced vapor injection flow path comprises a flash evaporator and an outdoor throttling device, wherein an inlet of the flash evaporator is communicated with the refrigerant input pipe through a first pipeline, an outlet at the gas side of the flash evaporator is connected with an air injection port of the enhanced vapor injection compressor through a second pipeline, an outlet at the liquid side of the flash evaporator is connected with the input end of the outdoor heat exchanger through a third pipeline, and the outdoor throttling device is arranged on the third pipeline;

the third pipeline is also provided with a first one-way valve which is in one-way conduction along the direction from the liquid side outlet of the flash evaporator to the input end of the outdoor heat exchanger;

and a first control valve capable of controlling the on-off of the second pipeline is arranged on the second pipeline.

2. The outdoor unit of claim 1, wherein,

the first control valve is an electromagnetic valve.

3. The outdoor unit of claim 1, wherein,

the first one-way valve is positioned between a liquid side outlet of the flash evaporator and the outdoor throttling device.

4. The outdoor unit of claim 1 or 2, wherein,

the outdoor throttling device comprises a throttling element; or

The outdoor throttling device comprises a plurality of throttling elements connected in parallel; or

The outdoor throttling device comprises at least one throttling element and a shunt electromagnetic valve, wherein the at least one throttling element is connected with the shunt electromagnetic valve in parallel.

5. The outdoor unit of claim 1 or 2, wherein,

the reversing device comprises a four-way valve, a second one-way valve, a third one-way valve, a fourth one-way valve, a fifth one-way valve and a sixth one-way valve, a first port of the four-way valve is communicated with an exhaust port of the enhanced vapor injection compressor through a fourth pipeline, a second port of the four-way valve is respectively connected with the input end and the output end of the outdoor heat exchanger through a fifth pipeline and a sixth pipeline, a third port of the four-way valve is respectively communicated with the refrigerant input pipe and the refrigerant output pipe through a seventh pipeline and an eighth pipeline, a fourth port of the four-way valve is communicated with a return port of the enhanced vapor injection compressor through a ninth pipeline, and the output end of the outdoor heat exchanger is also communicated with the refrigerant output pipe through a tenth pipeline;

the second one-way valve is arranged on the fifth pipeline and is communicated in a one-way mode in the direction from the second port to the input end of the outdoor heat exchanger;

the third one-way valve is arranged on the sixth pipeline and is communicated in a one-way mode in the direction from the output end of the outdoor heat exchanger to the second port;

the fourth one-way valve is arranged on the seventh pipeline and is communicated in a one-way mode in the direction from the refrigerant input pipe to the third port;

the fifth one-way valve is arranged on the eighth pipeline and is communicated in a one-way mode in the direction from the third port to the refrigerant output pipe;

and the sixth one-way valve is arranged on the tenth pipeline and is communicated in a one-way mode in the direction from the output end of the outdoor heat exchanger to the refrigerant output pipe.

6. The outdoor unit of claim 5, wherein,

and the outlet of the second one-way valve is positioned between the outdoor throttling device and the input end of the outdoor heat exchanger.

7. The outdoor unit of claim 5, wherein,

and a first gas-liquid separator is also arranged on the ninth pipeline.

8. The outdoor unit of claim 5, wherein,

the reversing device further comprises a second control valve, two ends of the second control valve are respectively communicated with the exhaust port and the refrigerant output pipe, and the second control valve is in a closed state in a pure refrigeration mode.

9. The utility model provides a two pipe heats and retrieves multi-online system which characterized in that includes:

the outdoor unit of an air conditioner according to any one of claims 1 to 8;

the air conditioner indoor units are connected in parallel;

and the refrigerant distribution device is arranged between the air conditioner outdoor unit and the plurality of air conditioner indoor units, is used for connecting the air conditioner outdoor unit and the plurality of air conditioner indoor units, and distributes refrigerants entering and exiting the plurality of air conditioner indoor units.

10. The two-pipe heat recovery multi-split air conditioning system of claim 9,

the refrigerant distribution device comprises a second gas-liquid separator, a main subcooler, a main throttling device, a plurality of refrigerating one-way valves, a plurality of heating one-way valves, a plurality of refrigerating electromagnetic valves and a plurality of heating electromagnetic valves which are connected through pipelines;

the inlet of the second gas-liquid separator is communicated with the inlet of the refrigerant distribution device, the liquid side outlet of the second gas-liquid separator is connected to the main path inlet of the main subcooler through a pipeline, the main throttling device is arranged between the main path outlet of the main subcooler and the auxiliary path inlet of the main subcooler, and the auxiliary path outlet of the main subcooler is connected to the outlet of the refrigerant distribution device through a pipeline;

the gas side outlet of the second gas-liquid separator is respectively connected to the first ends of the plurality of air-conditioning indoor units through the plurality of heating electromagnetic valves, the second ends of the plurality of air-conditioning indoor units are respectively connected to the main path inlet of the main subcooler through the plurality of heating one-way valves, and the plurality of heating one-way valves are in one-way conduction in the direction from the second ends of the plurality of air-conditioning indoor units to the main path inlet of the main subcooler;

the main path outlet of the main subcooler is respectively connected to the second ends of the air-conditioning indoor units through the refrigeration one-way valves, and the refrigeration one-way valves are in one-way conduction in the direction from the main path outlet of the main subcooler to the second ends of the air-conditioning indoor units; the first ends of the air-conditioning indoor units are respectively connected to the outlets of the refrigerant distribution device through the refrigeration electromagnetic valves.

11. The two-pipe heat recovery multi-split air conditioning system of claim 10,

the refrigerant distribution device further comprises a branch flow path, one end of the branch flow path is connected to any node between the outlet of the heating one-way valve and the main path inlet of the main subcooler, the other end of the branch flow path is connected to the outlet of the refrigerant distribution device, and a third control valve for controlling the on-off of the branch flow path is arranged on the branch flow path.

12. The two-pipe heat recovery multi-split air conditioning system of claim 11,

the number of the shunting branches is multiple, and the shunting branches are connected in parallel.

13. The two-pipe heat recovery multi-split air conditioning system of claim 11,

when the two-pipe heating recovery multi-split air conditioner system operates in a pure heating mode, the control system of the two-pipe heating recovery multi-split air conditioner system controls the opening degree of the main throttling device to be adjusted to the maximum, and controls the third control valve to conduct the shunting branch.

14. The two-pipe heat recovery multi-split air conditioning system of any one of claims 10 to 13,

the refrigerant distribution device further comprises an auxiliary subcooler and an auxiliary throttling device, a main path of the auxiliary subcooler is arranged between a liquid side outlet of the second gas-liquid separator and a main path inlet of the main subcooler, the auxiliary throttling device is arranged between a main path outlet of the auxiliary subcooler and a main path inlet of the main subcooler, and an auxiliary path of the auxiliary subcooler is arranged between an auxiliary path outlet of the main subcooler and an outlet of the refrigerant distribution device.